Improvement in bridges



W. E; THOMAS.

improvement in Bridges.

No.1 129,374, liatentedJuly1.6,1872.

Fly. 1.

im m: gnam] Wfl/iw .Wada/f Y w A ttumeg.

UNITED STATES PATENT OFFICE.4

WILLIAM E. THOMAS, OE QUEENsTowN, AssIGNoR To EIMsELE AND ROBERT w. RAsIN, OE BALTIMORE, MARYLAND.

IMPROVEMENT IN BRIDGES.

Specification forming part of Letters Patent No. 129,374, dated July 16, 1872.

Specication describing an Improvement in Bridges, invented by WILLIAM E.' THOMAS, Iof Queenstown, in the county of Queen Anne and State of Maryland. A

The invention consists in providing a bridge with a chute inwardly inclined against the current, with adjustable bolts to assist in supporting it under pressure, and with counterbalance weights.

Figure l is a cross-section; Fig. 2, a longil tudinal section.

A represents the channel of a stream, and B a bridge which spans it. C is a broad chute, inclined upward against the current, and attached to the under side of the bridge, so as to cause it to be lifted by the rising water. D D D D are four hollow upright guides, in which work the lateral projections b b b b of the bridge. To the top of each of these uprights is attached a fr xed nut, el, and an adjustable screw-bolt, d', by which the bridge.

The Inode of operation is as follows: As the stream takes a rise the current rushes against the inclined chute C and elevates the bridge in exact proportion to the increase in depth of water. When a loaded wagon or other vehicle comes along while the bridge is thus elevated the wagoner screws down the bolts d to such a distance as corresponds with the rise of bridge, and thus prevents the weight of his loaded wagon from submerging it.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A bridge, B, provided vwith a chute, C, thereunder,as and for the purpose described.

2. A bridge, .B, that rises and falls with stream,l in combination with the vertical adjustable screw-bolts d, arranged as and for .the purposedescribed.

3. A bridge that rises and falls with stream, combined with chute resting upon water and counter-balance weights to support it under pressure from above, as described.

4. The chute C, supporting-bolts d', and counter-balance weights, combined with a bridge having the lateral projections b, as and for the purpose described.

WILLIAM E. THOMAS.

Witnesses:

SoLoN (l. KEMON, THos. D. D. OURAND. 

